Typically, electronic devices include one or more camera modules for providing enhanced media functionality. For example, the typical electronic device may utilize the camera modules for photo capturing and video teleconferencing. In the typical electronic device with multiple camera modules, the primary camera module has a high pixel density and an adjustable focus lens system, while the secondary camera module is front-facing and has a lower pixel density. Also, the secondary camera module may have a fixed focus lens system.
For example, U.S. Patent Application No. 2009/0057544 to Brodie et al, assigned to the present application's assignee, discloses a camera module for a mobile device. The camera module comprises a lens, a housing carrying the lens, and a lens cap over the lens and housing. The camera module includes a barrel mechanism for adjusting the lens. During manufacture of an electronic device including one or more camera modules, there is a desire to manufacture the electronic device as quickly as possible, particularly in mass production runs.
The typical camera module is manufactured in a multi-step process. The first steps include semiconductor processing to provide the image sensor integrated circuit (IC). The next steps include some form of testing for the image sensor IC and packaging. The image sensor IC may be assembled into the camera module, along with a lens and movable barrel if needed. This assembly of the camera module may be performed manually or via machine. For example, in electronic devices that use surface mounted components, a pick-and-place (PNP) machine may assemble the components onto a printed circuit board (PCB). A drawback to such singular packaging is that it may be relatively inefficient and also may require that each device be tested individually, adding to the manufacturing time.
In some applications, it may helpful to manufacture the image sensor IC to include an infrared (IR) filter glass. In one approach, an IR filtering glass is attached over the image sensor IC. A potential drawback to this approach is that the overall thickness of the device may be increased, which may be undesirable for tight fitted mobile applications.
Referring to FIG. 1, an approach to an image sensor device 20 is shown. The image sensor device 20 illustratively includes an interconnect layer 21, an image sensor IC 22 on the interconnect layer, an adhesive layer 29 between the image sensor IC and the interconnect layer, and a plurality of bond wires 23a-23a coupling the image sensor IC to the interconnect layer. The image sensor device 20 illustratively includes a filter holder 25, an IR filter 26 on the filter holder, and an adhesive layer 24 between the filter holder and the interconnect layer 21. Also, the image sensor device 20 illustratively includes a lens module 27 over the IR filter 26, and an adhesive layer 72 coupling the lens module and the filter holder 25 together. The interconnect layer 21 illustratively includes a plurality of contacts 71. The image sensor device 20 illustratively includes another adhesive layer 73 between the IR filter 26 and the filter holder 25.